Mayor Richard Daley teed off Tuesday on Republican presidential candidate John McCain for including Daley's brother in a negative ad about Barack Obama's Chicago political roots.

The TV ad claims that Democratic presidential candidate Obama, a U.S. senator from Illinois, was "born of the corrupt Chicago political machine." The commercial seeks to link Obama to four power-brokers: the mayor's brother Bill, convicted former fundraiser Antoin "Tony" Rezko, Obama mentor and Illinois Senate President Emil Jones and embattled Democratic Gov. Rod Blagojevich.

"People get desperate in their political life," the mayor said when asked about the ad. "My theory about politics and government: You build yourself up. You don't have to tear people down."

Daley also warned that McCain has his own vulnerabilities, noting the Arizona senator's involvement in the "Keating Five" influence-peddling scandal that involved his ties to banker Charles Keating Jr., a poster boy for the savings-and-loan meltdown.

"If people start throwing dirt and mud -- remember, it comes back and hits you right in the face," the mayor said. "I think, to put my brother Bill there ... they want to put me there, fine, they put me there all the time anyway."

The ad described Bill Daley, a former U.S. Commerce secretary, as a "lobbyist" and "the mayor's brother."

"First of all, my brother is not a lobbyist. He's not a lobbyist. He's not a lobbyist. He's never been a lobbyist," the mayor said.

In fact, Bill Daley was a key Washington lobbyist for top U.S. and foreign companies, and President Bill Clinton picked him to lobby Congress for passage of the North American Free Trade Agreement. When he was president of SBC Communications Inc. in 2003 he coordinated lobbying campaigns to sway both state and federal lawmakers.

The mayor, an early Obama supporter who has had a good relationship with Republican President George W. Bush, questioned whether anyone who runs such an ad is "worthy" of being president.

"I respect the candidates running for president on both sides of the aisle. I don't have to bring their family in an ad, to really do disservice. ... you see an ad about Sen. McCain's wife and how wealthy they are? That would be unfair," Daley said.

"People love money. Some love sex. Some love drugs. Some love power. It's human frailties," Daley said. Asked whether he is suggesting a Keating Five ad, Daley shot back: "It would be a great ad. People lost their life savings. Life savings, their own homes, for a guy named Keating out of Arizona.

"You want to get tough in politics, I can get tough in politics as anyone else," Daley said. "When you start throwing mud, mud is going to be thrown at you and it's going to be sticky."